DESCRIPTION (provided by investigator): Lyme disease, caused by the gram-negative spirochete Borrelia burgdorferi and transmitted by Ixodid tick species, is the leading vector-borne infectious disease in the United States, with a steady rise in the number of cases reported each year. The most common Lyme disease symptom, the classic bull's-eye rash (erythema migrans or EM rash) in endemic areas, can indicate the need for immediate treatment without accompanying diagnostic testing. However, 3-10% of Lyme disease cases proceed to less well diagnosed secondary symptoms without presentation or recognition of the EM rash. Current diagnostic testing consists of a two-tier system, as recommended by the Centers for Disease Control and Prevention. The first tier test is an enzyme-linked immunosorbent assay (ELISA); the second tier consists of immunoblot (IB) analysis. The inherent flaw of the most commonly used first tier ELISA test, using whole cell sonicate (WCS), is its lack of specificity to B. burgdorferi antigens, yielding a high false positive rate. Additionally, the second-tier IB is costly, time-consuming, and technically challenging. As a result, recent efforts have focused on developing a single tier test format by increasing the specificity of the ELISA through the use of single or combinations of recombinant and peptide antigens. Although more than 70 serological Lyme disease tests have been developed and approved by the FDA, none has succeeded in replacing the WCS ELISA and the two-tier testing format, due to similar levels of false positives and/or additional false negatives due to insufficient antigen presentation. Agave BioSystems has developed a wide range of multiplex microsphere assays, capable of simultaneously and quantitatively detecting individual serum antibody responses to a panel of antigens. This technology enables high throughput evaluation of serum responses to individual antigens and combinations of antigens and has been validated against ELISA and IB results. Therefore, Agave BioSystems proposes to develop a Borrelia burgdorferi microsphere assay capable of replacing the Lyme disease two-tier test format. The microsphere assay will maintain the requisite level of sensitivity, while providing a significant improvement in specificity over the WCS ELISA and broader antigen coverage compared to peptide and recombinant antigen ELISA assays. In the Phase II, a multiplex assay will be developed that allows quantifiable serum antibody response to over ten different antigens within a single multiplex assay. PUBLIC HEALTH RELEVANCE: Lyme disease is the leading vector-borne infectious disease in the United States, with a steady rise in the number of cases reported each year. Current diagnostic testing consists of a two-tier system which is time-consuming, technically challenging, and has a high false positive rate. Agave BioSystems proposes to develop a Borrelia burgdorferi microsphere assay capable of replacing the Lyme disease two-tier test format. This microsphere assay will maintain the requisite level of sensitivity, while providing a significant improvement in specificity over the WCS ELISA and broader antigen coverage compared to peptide and recombinant antigen ELISA assays. [unreadable] [unreadable] [unreadable]